Nanocomposite formation synthetic routes

In further quest for development of more efficient materials, clue had been provided by ongoing mixed (interdisciplinary) research. Intelligently the immediate inspiration was drawn from mixed systems (i.e., blends, alloys or composites) based on conventional polymers, metals, and ceramics. Soon it was realized that the already established wide applicability of CPs/ICPs can be further expended by formation of multiscale/multiphase systems, e.g., a wide variety of electronically, electrochemically, and/or optoelec-tronically active blends (BLNs), conjugated copolymers (CCPs) and composites (CMPs) [both bulk or nanocomposites (NCs)] or hybrids (HYBs) [11,14-16,52,109,113,120,128,131,132,191-205]. The next section of the chapter covers the fundamental aspects of CP-based BLNs, CCPs, and NCs/ HYBs. In particular, their definitions (including etymology), types, properties, synthetic routes, and practical applications have been discussed with the help of suitable examples from the open literature. 

Another nanofiller type that has been used for PA nanocomposite formation through the IPC method are CNTs. Indeed, HaggenmueUer et al. [80] adapted this method for the fabrication of PA 6.6-SWNTs nanocomposites. In their synthetic route, SWNTs were incorporated suspended either in water or in toluene. The quality of the nanofiller suspension prior to the in-situ polymerization, also in this case, was found to determine to a large extent the nanofUler dispersion in the... 

As for the thermodynamic consideration in Section 2.2.1, we attempt to highlight these challenges by describing in some detail the most common synthetic routes for nanocomposite formation employed for polymer/layered-inorganic hybrids. Most examples are drawn from layered-silicate fillers, but the conclusions are general across most nanofillers, and one should be able to envision similar strategies for nanocomposite formation based on other types of nanofillers. 

In other studies [307, 308], this same group produced bionanocomposites by melt intercalation of PCL and MMT modified by various alkylammonium cations. Depending on whether the ammonium cations contain nonfunctional alkyl chains or chains terminated by carboxylic acid or hydroxyl functions, microcomposites or nanocomposites were produced. The layered silicate PCL nanocomposites exhibited some improvement in mechanical properties and increased thermal stabihty as well as enhanced flame retardancy. The authors concluded that formation of PCL-based nanocomposites, not only depended on the nature of the ammonium cation and its functionaHty, but also on the selected synthetic route, that is, melt intercalation versus in situ intercalative polymerization. 

The research around the use of montmorillonite to obtaining nanocomposites polymer-MMT has become even more intense. In a review, Biswas and Ray [45] described several features of polymer-MMT nanocomposite materials. Ray and Okamoto [24] reported various characteristics of polymer-layered silicate nanocomposite materials, some of these materials exhibited distinctive properties like biodegradability. Ahmadi et al. [46] reviewed synthetic routes, properties, and future applications of polymer-layered nanocomposites. Significantly, nanocomposites of PAni and PPY with MMT clay via emulsion polymerization technique [47, 48] were found to act as electrorehological fluids, sometimes denominated smart fluids. In this context, Ballav and Biswas [49, 50] reported high yield oxidative polymerization of thiophene, aniline, pyrrole, and furan by MMT— without extraneous oxidant—vis-a-vis nanocomposites formation of the corresponding polymers with MMT. 

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